1. Field of the Invention
The present invention relates to a method of constructing a slope protection by placing a bag-like mat over the soil of a slope, followed by placing a concrete or a soil into the bag-like mat, followed by vegetation and subsequent greening of the slope.
2. Description of the Prior Art
A conventional bag-like fabric mat which is filled with a concrete, a soil or the like to construct a slope protection is shown here in FIGS. 5(a) and 5(b) of the accompanying drawings. The mat 1 is made of synthetic fiber such as nylon and includes a two-ply or double-layered portion 2 having an internal space defined between front and back layers of the mat for receiving therein the concrete, for example, and a single-ply or single-layered portion 3 free of the internal space. The conventional mat thus constructed has a problem that the single-layered portion 3 can exist for a long period of time without deterioration and hence prevents vegetation and subsequent greening of the slope. To deal with this problem, the single-layered portion 3 is cut out or removed after the concrete is placed in the mat, as shown in FIG. 5(c). Now, vegetation and subsequent greening of the slope is possible. However, this method still has a drawback that it is time-consuming because a cutting work due for removing a portion of the bag-like mat should be achieved in a process of construction of the slope protection. Another drawback is that the bag-like mat is comparatively expensive because an effectively usable portion of the fabric is relatively small.